The invention relates to a compression device for an X-ray diagnostic apparatus, comprising a compression carriage which is adjustable by means of an electromotor,said compression carriage supporting a compression localizer with which switching means are associated which disconnect the motor when the compression localizer engages the radiography subject.
An X-ray diagnostic apparatus comprising a compression carriage of this type is known which serves the purpose of preparation of radiographs of the human female breast. The radiography subject is placed on a radiographic plate and subsequently compressed by motor means. The motor for the compression carriage is automatically disconnected by spring-loaded switching means when the force on the radiography subject attains a predetermined value.
In the case of the known compression device, a sudden, i.e. not a sensitive, disconnection of the motor for the compression device takes place. As a consequence of the inertia of the moved parts it is possible for the force on the radiography subject to further increase in an undesired manner after the disconnection of the motor.
From the German OS No. 2,356,276, it is already known in the case of an X-ray spot film device to switch over the speed of the drive motor in a stepwise fashion in dependence upon the force acting on the patient.